Ōki

Ōki Kōgaku Seiki Seisaku-sho (大木光学精機製作所, i.e. "Ōki precision machinery factory") was a Japanese company based in Tokyo, Arakawa. It was the producer of two cameras during the Second World War, the Oko Six and Oko Semi. It probably made the four-element Oko or Okor lenses mounted on these cameras. It also made Hildar and Oscar lenses for the Semi Rosen U and Primo distributed by Ōsawa Shōkai.

Camera list

• Oko Six I and II (6×6 folder)
• Oko Semi (4.5×6 folder)

Lens list

• Hildar 75/4.5 on the Semi Rosen U, also reported on an example of the Semi Lucky
• Hildar 75/3.5 on the Semi Rosen U
• Oscar 75/4.5 on the Primo I
• Oscar 75/3.5 on the Primo II
• Okor (or Oko) 75/3.5 on the Oko Six and Oko Semi

The Hildar and Oscar lenses have three elements and are probably identical. The Oko or Okor lens has four elements.

Bibliography

• "Kokusan shashinki no genjōchōsa" (国産写真機ノ現状調査, Inquiry into Japanese cameras), listing Japanese camera production as of April 1943. Reproduced in Supuringu kamera de ikou: Zen 69 kishu no shōkai to tsukaikata (スプリングカメラでいこう: 全69機種の紹介と使い方, Let's try spring cameras: Presentation and use of 69 machines). Tokyo: Shashinkogyo Syuppan-sha, 2004. ISBN 4-87956-072-3. Pp.180–7.
• McKeown, James M. and Joan C. McKeown's Price Guide to Antique and Classic Cameras, 12th Edition, 2005-2006. USA, Centennial Photo Service, 2004. ISBN 0-931838-40-1 (hardcover). ISBN 0-931838-41-X (softcover).

Its address in 1943 was Tōkyō-to Arakawa-ku Ogu-chō 3–2069 (東京都荒川区尾久町3–2069). Source: "Kokusan shashinki no genjōchōsa" ("Inquiry into Japanese cameras"), listing the Japanese camera production as of April 1943.

Semi Lucky example pictured in McKeown, p. 572.

"Kokusan shashinki no genjōchōsa" ("Inquiry into Japanese cameras"), lens items Lb27, Lb28, Lc6 and Lc7. In the document, the maker's name is missing for the Oscar 75/3.5, but it was surely made by Ōki too.

Advertisements reproduced in Kokusan kamera no rekishi, p. 61.